Long length imaging method and device based on digital radiography

ABSTRACT

This invention concerns digital radiography, especially in relation to a long-length imaging method based on digital radiography, as well as a digital radiography device, an image processing system and a computer-readable memory medium to implement the method. According to one respect of the invention, the long-length imaging method based on digital radiography comprises the following steps: A. determining a part of interest of an anatomy of an object; B. determining imaging parameters of digital radiography based on the part of interest, the imaging parameters at least including a plurality of specified positions of imaging components, wherein the plurality of specified positions are configured to make X-ray images captured at the plurality of specified positions by the imaging components include the part of interest of the anatomy of the object; and C. generating a long-length image in relation to the part of interest of the anatomy of the object based on the X-ray images at the plurality of specified positions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to counterpart Chinese PatentApplication No. 202110240072.3, filed Mar. 4, 2021, in the ChinaNational Intellectual Property Administration, in the name of Sun etal., and entitled METHOD AND SYSTEM FOR AUTOMATIC LONG LENGTH IMAGING.

TECHNICAL FIELD

This invention relates to digital radiography, especially to along-length imaging method based on digital radiography as well as adigital radiography device, an image processing system and acomputer-readable memory medium to implement the method.

BACKGROUND ART

As a clinic imaging tool, the DR (digital radiography) system is beingemployed widely in the medical domain and also in the industrial domain.As illustrated in FIG. 1, the radiation of an X-ray source 110 of a DRdevice 10 passes through a patient or object PA and beams onto aradiation detector 120, wherein the detector, for example, may include ascintillator screen 121 and an image sensing array 122. The scintillatorscreen 121 is intended to convert energy from ionization radiation tolight radiation of different frequencies. And, the image sensing array122 is usually mounted on the back of the scintillator screen or coupledoptically to the scintillator screen, which, as such, receives emittedlight excited by incident radiation and creates digital images. Thedigital images created this way may be processed and displayed by animage processing unit, and such functions are rendered normally by acomputer work station and a display 130.

In many clinic applications, it is necessary to image a relatively largeportion of body anatomy (e.g., the spine or a whole leg bone). Under therestraint of cost and technology, the size of a detector is greatlylimited as well, which results in the complication in the process oflong-length imaging. According to some long-length imaging technologiesset forward to work with a DR system, a larger composite image isre-created by acquiring a series of exposures/images in differentpositions (a patient is required to remain still in such a process) andthen stitching the individual images together. However, in the existinglong-length imaging technologies, operators are required to set,according to experience, parameters such as exposure times or times ofimage capture and overlapping extent of images of two adjacent captures,so as to subsequently determine, based on the parameters, the initialposition and the subsequent position of an X-ray source and a radiationdetector. The introduction of human factors makes the operationcomplicated and cumbersome with an unstable imaging quality.

Thus, it is necessary to provide a long-length imaging method and devicebased on digital radiography to address the problem noted above.

SUMMARY IN INVENTION

This invention is intended to provide a long-length imaging method basedon digital radiography, as well as a digital radiography device, animage processing system and a computer-readable memory medium toimplement the method.

In the light of one aspect of the invention, the long-length imagingmethod based on digital radiography comprises the following steps:

-   -   A. determining a part of interest of an anatomy of an object;    -   B. determining imaging parameters of digital radiography based        on the part of interest, the imaging parameters at least        including a plurality of specified positions of imaging        components, wherein the plurality of specified positions are        configured to make X-ray images captured at the plurality of        specified positions by using the imaging components include the        part of interest of the anatomy of the object; and    -   C. generating a long-length image in relation to the part of        interest of the anatomy of the object based on the X-ray images        at the plurality of specified positions.

Alternatively, step A of the long-length imaging method noted abovecomprises:

-   -   A1. generating, from an image presenting external features of        the object, a body pose image suitable to depict the anatomy of        the object, the body pose image including key nodes of the        anatomy and line segments indicating relevance between the key        nodes; and    -   A2. determining the line segments having relevance to the part        of interest in the body pose image.

Alternatively, in step A1 of the long-length imaging method noted above,an identification algorithm of human body pose is employed to locate thekey nodes of the anatomy.

Alternatively, in the long-length imaging method noted above, the keynodes include one or more of the following parts: neck, shoulder, wrist,elbow, rib, hip, crotch, knee and ankle.

Alternatively, step A of the long-length imaging method noted abovecomprises:

-   -   A1′. determining, by using an image segmentation algorithm, a        contour of the object in the image presenting the external        features of the object to generate a contour image depicting the        contour of the object; and    -   A2′. determining, in the contour image, a contour portion having        relevance to the part of interest according to a proportional        relation between every parts of the anatomy of the object in a        specific body pose.

Alternatively, in the long-length imaging method noted above, the partsof interest include one of the following parts: spine, leg bone and armbone.

Alternatively, in the long-length imaging method noted above, theimaging components comprises a X-ray source and a detector.

Alternatively, step B of the long-length imaging method noted abovecomprises:

-   -   B1. mapping the line segments having relevance to the part of        interest in the body pose image to an imageable space of the        imaging components;    -   B2. determining boundaries of the line segments in the imageable        space; and,    -   B3. determining the plurality of specified positions of the        imaging components based on the boundaries.

Alternatively, in step C of the long-length imaging method noted above,the X-ray images captured at the plurality of specified positions arestitched together with an image stitching algorithm to generate thelong-length image in relation to the parts of interest of the anatomy ofthe object.

In the light of another aspect of the invention, the digital radiographydevice comprises:

-   -   an imaging unit, comprising a X-ray source and a radiation        detector as imaging components;    -   a control unit, configured to control an imaging process of the        imaging unit based on imaging parameters; and    -   an image processing unit configured to:    -   A. determine a part of interest of an anatomy of an object;    -   B. determine, based on the part of interest, the imaging        parameters required by the control unit to control the imaging        process, the imaging parameters at least including a plurality        of specified positions of the imaging components, wherein the        plurality of specified positions are configured to make X-ray        images captured by the imaging components include the part of        interest of the anatomy of the object at the plurality of        specified positions; and    -   C. generate a long length image in relation to the part of        interest of the anatomy of the object based on the X-ray images        captured at the plurality of specified positions.

In the light of another aspect of the invention, image processing systemcomprises:

-   -   a memory;    -   a processor; and,    -   a computer program stored in the memory and executable by the        processor, wherein the running of the program enables the steps        included in the method as delineated above to be implemented.

In the light of another aspect of the invention, the computer-readablememory medium with a computer program stored therein is included,wherein the steps included in the long-length imaging method based ondigital radiography as described above are implemented when the computerprogram is executed by a processor.

In one or more embodiments of this invention, the body pose imagesuitable to depict the anatomy of the object is employed to determine inthe anatomy the boundary of the part of interest within the imageablespace and, thus, enable the automatic determination of the plurality ofimaging positions, thereby excluding the interference from humanfactors, simplifying operation steps and eliminating the instability ofimaging quality. Moreover, a body pose image is used in the prior art toidentify the pose of a human body; however, by diverting it in one ormore embodiments of this invention, fast determination of a part ofinterest in anatomy may be enable. Because of the intuitive form ofpresentation, this facilitates the operation of users as well.Furthermore, the employment of an identification algorithm of human bodypose during generation of a body pose image to identify key nodes mayuse the algorithm to the maximum advantage in respect of source openingand maturity, which will favor development acceleration and costreduction.

BRIEF DESCRIPTION ON DRAWINGS

With the following description with figures in every respect, theadvantages in above and/or other aspects of this invention will becomemore explicit and apprehensible more easily. In the figures, theidentical or similar units are marked with the same number. The figurescomprise:

FIG. 1 is a schematic diagram illustrating a digital radiography deviceof the prior art.

FIG. 2 is a schematic block diagram illustrating the digital radiographydevice according to an embodiment of this invention.

FIG. 3 is a flow chart illustrating the long-length imaging method basedon digital radiography according to another embodiment of thisinvention.

FIG. 4 is a flow chart illustrating the method for determining a part ofinterest of the anatomy of an object according to another embodiment ofthis invention.

FIG. 5A is a body pose image depicting a front view of the anatomy of anobject in the state of standing.

FIG. 5B is a body pose image depicting a side view of the anatomy of anobject in the state of standing.

FIG. 6 is a flow chart illustrating the method for determining a part ofinterest of the anatomy of an object according to another embodiment ofthis invention.

FIG. 7 shows an example embodying the use of an image segmentationalgorithm to determine a contour of an object in an image presentingexternal features of the object.

FIG. 8 is a flow chart illustrating the method for determining imagingparameters according to another embodiment of this invention.

FIG. 9 is a schematic block diagram illustrating the image processingsystem according to another embodiment of this invention.

EMBODIMENTS

This invention will be elaborated more comprehensively in the followingparts by reference to the figures depicting schematic embodiments of theinvention. However, the invention may be implemented in different forms,and shall not be interpreted as one solely limited to the embodimentspresented in the text. The embodiments noted here are intended for athorough and complete disclosure and, to the end, communicate theprotection scope of the invention more comprehensively to personsskilled in the art.

In the Specification, expressions such as “include” and “comprise” arenot restricted to indicting that there only exist the units and stepsthat are described directly and definitely in the Specification and theClaims; instead, the technical solution of this invention does notexcept the existence of other units and steps that are not directly anddefinitely described.

Also, expressions like “first” and “second” do not indicate the sequenceof units in respect of time, space, size, etc., which, however, aredevised purely to differentiate between units.

FIG. 2 is a schematic block diagram illustrating the digital radiographydevice according to an embodiment of this invention.

A digital radiography device 20, as illustrated by FIG. 2, comprises animaging unit 210, a control unit 220 and an image processing unit 230.Alternatively, the digital radiography device 20 may further include animage capture device 240 (e.g., camera).

An imaging unit 210 comprises an X-ray source 211 and a radiationdetector 212 opposite to the X-ray source 211. In the process ofimaging, the radiation generated by the X-ray source 211, afterpenetrating through a patient or object, beams onto the radiationdetector 212. A scintillator screen of the detector converts energy fromionization radiation to light radiation of different frequencies;subsequently, an image sensing array of the detector forms a digitalimage based on the light radiation. In this embodiment, at least one ofthe X-ray source 211 and the radiation detector 212 is moveable (e.g.,under the control of control unit 220, a motor moves the X-ray source211 or the radiation detector 212 to an specified position) to image thepatient or object.

A control unit 220 is coupled to the imaging unit 210 and configured tocontrol the operation of the imaging unit in an imaging process. Forexample, the control unit 220 may instruct a motor to move the X-raysource 211 or the radiation detector 212 to an specified position, exertcontrol over the strength and time of exposure and so forth.

In the digital radiography device as illustrated by FIG. 2, an imageprocessing unit 230 is coupled to the radiation detector 212 andconfigured to process images captured by the radiation detector 212 bydiverse means (e.g., configured to stitch together X-ray images capturedat a plurality of specified positions by using an image stitchingalgorithm, adjust the contrast of an image, correct the distorted regionof an image and so forth). In this embodiment, the image processing unit230 is further configured to generate image parameters required inlong-length imaging and transmit the generated imaging parameters to thecontrol unit 220. The imaging parameters noted here include but are notlimited to, for example, a plurality of specified positions of the X-raysource 211 and/or the radiation detector 211 configured to capture X-rayimages, and the overlapping extent of X-ray images captured in adjacentspecified positions. The generation mode of the imaging parameters willbe delineated in the following parts.

An image capture device 240 (e.g., camera) is coupled to the imageprocessing unit 230 and configured to acquire an image presentingexternal features of a patient or object. The external features notedhere include but are not limited to the external shape of an object, thecolor, character and texture of the body surface or clothing of anobject and so forth.

In this embodiment, the captured image of external features of thepatient or object will be used by the image processing unit 230 togenerate the imaging parameters. The specific way of such use will bedelineated in the following parts. Alternatively, the image capturedevice 240 may be arranged close to the radiation detector 212 and bemade suitable to capture a full-length or half-length image of thepatient or object.

FIG. 3 is a flow chart illustrating the long-length imaging method basedon digital radiography according to another embodiment of thisinvention.

As an example, the digital radiography device illustrated in FIG. 2 isused to implement the method of FIG. 3. However, it is necessary topoint out that the implementation of the method according to thisembodiment is not limited to a digital radiography device with thespecific structure shown in FIG. 2.

In step S301 as illustrated in FIG. 3, an image capture device 240captures an image presenting external features of a patient or objectand transmits them to an image processing unit 230. As an example,provided it is required to photograph an X-ray image of the patient'sspine, an operator may ask the patient to stand or lie and instruct theimage capture device 240 to take an image of the patient's upper-halfbody (a color image or a black-and-white one).

Subsequently in step S302, the image processing unit 230 determines apart of interest of the anatomy of the object (e.g., spine, leg bone andarm bone). Such a means of determining the part of interest of theanatomy of the object will be delineated below in combination with theembodiment presented in FIG. 4.

In step S303 subsequent to step S302, the image processing unit 230,based on the part of interest determined in step S302, generates imagingparameters required in the implementation of long-length imaging, andtransmit them to the control unit 220 so as to use the imaging unit 210to capture X-ray images at a plurality of specified positions. In thisembodiment, the imaging parameters include a plurality of specifiedpositions of imaging components (e.g., an X-ray source 211 and aradiation detector 212). The plurality of specified positions aredefined as those where the imaging components are used to capture X-rayimages that can include a part of interest of the anatomy of an object.Alternatively, these specified positions may be represented by a timesequence—the order in which the specified positions appear in the timesequence exactly indicates the order in which the X-ray source 211 andthe radiation detector 212 appear in such positions. Alternatively, theimaging parameters further include the overlapping extent of the X-rayimages captured in adjacent specified positions. Such a means ofdetermining the imaging parameters will be delineated below incombination with the embodiment presented in FIG. 6.

Subsequently in step S304, under the control of control unit 220, theX-ray source 211 and the radiation detector 212 of the imaging unit 210are positioned in a new specified position in the time sequence so as tocapture X-ray images in such a specified position, and the capturedX-ray images are transmitted to the image processing unit 230. If thisstep is executed first time, the new specified position will indicatethe initial position of the X-ray source 211 and the radiation detector212 or the first specified position in the time sequence; if it is notthe first time to execute the step, the new specified position willindicate an specified position subsequent immediately to the specifiedposition where the X-ray source 211 and the radiation detector 212exercise step S304 last time.

Subsequently in step S305, the control unit 220 determines whether allthe specified positions in the time sequence have been experienced. Ifthe answer is Yes, the process will go to step S306; otherwise, theprocess will return to step S304.

In step S306, the image processing unit 230 uses an image stitchingalgorithm to stitch together the X-ray images captured at the pluralityof specified positions so as to generate a long-length image in relationto the part of interest of the anatomy of the object. As an example,provided the radiation detector and the X-ray source move only in onedirection, the overlapping extent of the X-ray images captured in theadjacent specified positions may be determined based on the equationbelow:

R _(n) =X/2-(H _(n+1)-H _(n))/2  (1)

Here, n denotes the sequence number of an specified position, R_(n)denotes the overlapping extent between an image captured in the(n+1)^(th) imaging position and an image captured in the n^(th) imagingposition, X denotes the physical size of a radiation detector in themoving direction, and H_(n) and H_(N+1) denote the coordinates of then^(th) imaging position and the (n+1)^(th) imaging positionrespectively.

FIG. 4 is a flow chart illustrating the method for determining a part ofinterest of the anatomy of an object according to another embodiment ofthis invention. The method according to FIG. 4 may be applied to stepS302 as shown by FIG. 3.

According to step S401 illustrated by FIG. 4, the image processing unit230 generates a body pose image describing the anatomy of the object byidentifying or positioning, in the image presenting the externalfeatures of the object, key nodes of the anatomy and by determining thekey nodes in pairs having relevance.

The key nodes noted here are ordinarily corresponding to the object'sparts with a certain degree of freedom, including but not limited to theparts such as neck, shoulder, wrist, elbow, rib, hip, crotch, knee andankle.

The relevance noted here may be defined based on the imaging requirementof the anatomy of the object. For example, the digital radiography isoften used to image parts, such as the spine, leg bones and arm bones ofa patient of object; for this purpose, relevance may be establishedbetween the shoulders and the elbows (corresponding to the upper armbones), between the elbows and the wrists (corresponding to the lowerarm bones), between the neck and the crotches (corresponding to thespine), between the crotches and the knees (corresponding to the upperleg bones), between the knees and the ankles (corresponding to the lowerleg bones) and so forth. Alternatively, the relevance between the keynodes in pairs may be represented by line segments connecting the keynodes. As the line segments connecting key nodes are used to indicatethe relevance, the line segments may represent a specific part of theanatomy (such as upper arm bone, lower arm bone, upper leg bone andspine).

FIG. 5A is a body pose image depicting a front view of the anatomy of anobject in the state of standing, and FIG. 5B is a body pose imagedepicting a side view of the anatomy of an object in the state ofstanding. As illustrated in FIGS. 5A and 5B, key nodes and line segmentstherebetween are all drawn on an image presenting the external featuresof an object; that is, the body pose image presenting the anatomy of theobject is drawn by means of overlaying the image presenting the externalfeatures of the object.

Referring to FIGS. 5A and 5B, the numbers in the figures are serialnumbers denoting the key nodes of the anatomy. For example, “1” denotesneck, “2” and “5” denote shoulders, “3” and “6” denote elbows, “4” and“7” denote wrists, “8” and “11” denote crotches, “9” and “12” denoteknees and “10” and “13” denote ankles. In FIG. 5A, when two key nodesare connected by a line segment, relevance will be established betweenthis pair of key nodes; that is, the line segment connecting this pairof key nodes represents a specific part in the anatomy (e.g., the linesegment between the key nodes “8” and “9” represents the left upper legbone or the right upper leg bone).

Identification algorithms of human body, such as Openpose, would usuallyestimate a human body pose by connecting key points of a human bodydetected in an image. In step S401, alternatively, the identificationalgorithm of human body may be employed to generate a body pose image.As shall be noted, although a pose of the object is not necessary forthe generation of the imaging parameters in this embodiment, since thehuman body key points detected by an identification algorithm of humanbody have a similarity to the key nodes in this embodiment (which iscorresponding to parts having a certain degree of freedom on the body ofan object), the existing identification features of key points for anidentification algorithm of human body may be applied to identificationof the key nodes. In terms of the properties of source opening andmaturity, the application of identification algorithms of human body tokey node identification will favor development acceleration and costreduction.

Subsequently in step S402, the image processing unit 230 determines theline segments having relevance to the part of interest in a body poseimage. As shall be noted, the part of interest here may include not onlyone specific part of the anatomy (e.g., an upper leg bone, a lower legbone, an upper arm bone or a lower arm bone), but also a plurality ofspecific parts of the anatomy (e.g., a complete leg bone or a completearm bone). That is, the line segment having relevance to the part ofinterest may be one or a plurality of line segments in a body poseimage.

FIG. 6 is a flow chart illustrating the method for determining a part ofinterest of the anatomy of an object according to another embodiment ofthis invention. The method illustrated by FIG. 6 may be applied to stepS302 shown in FIG. 3.

In step S601 as illustrated by FIG. 6, the image processing unit 230uses an image segmentation algorithm to determine an contour of theobject in the image presenting external features of the object so as togenerate a contour image describing the object's contour. The examplecited here in relation to the image segmentation algorithm includes butis not limited to segmentation algorithms based on threshold values,segmentation algorithms based on areas, segmentation algorithms based onedges and so forth. FIG. 7 gives an example about determining a contourof an object in an image presenting external features of the object withan image segmentation algorithm.

Subsequently in step S602, the image processing unit 230 determines acontour portion having relevance to the part of interest according to aproportional relation between every parts of the anatomy of the objectin a specific body pose. As an example, the proportional relationbetween every parts of the anatomy may be determined based on thestatistic derived from a large quantity of samples. Moreover, though theproportional relation between every parts of the anatomy might vary dueto a change in the body pose, only a small number of types of poseswould normally be used during digital photography and, therefore, therequirements of application would be met by storing the proportionalrelations corresponding to these poses in advance and invoking them whenthey are needed for use.

The relevance noted here is also defined based on the imagingrequirement of the anatomy of the object. For example, as digitalradiography is used to image the parts such as the spine, the leg boneand the arm bone of the patient or object, the contour portionsdetermined are respectively the contours of parts such as the trunk, theupper leg and the arm.

FIG. 8 is a flow chart illustrating the method for determining imagingparameters according to another embodiment of this invention. The methodillustrated by FIG. 8 may be applied to step S303 shown in FIG. 3.

Once the imaging parameters of the external features of the patient orobject (e.g., focus) are determined, the line segments indicating theparts of interest of the anatomy may be mapped from the body pose imageinto a real physical space (e.g., an imageable space of the imagingcomponents), or contour portions indicating the parts of interest of theanatomy may be mapped from the contour image into a real physical space(e.g., an imageable space of the imaging components). The imageablespace noted here refers to such a space, in which, by moving the imagingcomponents to every accessible position, the patient or object may beimaged by the imaging components (e.g., the X-ray source and theradiation detector), and out of which the patient or object may not beimaged by the imaging components (e.g., the X-ray source and theradiation detector).

In another aspect, the line segment indicates the extension range orboundary of the part of interest of the anatomy in the body pose image.Since the extension range has a unique corresponding extension range orboundary in the real physical space, the coordinates of the part ofinterest of the anatomy in the imageable space may be obtained bymapping the body pose image to the imageable space (i.e., conversion ofthe coordinates), whereby corresponding imaging parameters aredetermined.

In terms of the contour portion of the part of interest of the anatomy,its boundary in the contour image also has a unique correspondingextension range or boundary in the real physical space; thus, thecoordinates of the part of interest of the anatomy in the imageablespace may be obtained by mapping the contour image to the imageablespace (i.e., conversion of the coordinates), whereby correspondingimaging parameters are determined.

In step S801 as illustrated by FIG. 8, the image processing unit 230invokes the imaging parameters of the image presenting the externalfeatures of the patient or object.

Subsequently into step S802, the image processing unit 230, based on theinvoked imaging parameters, maps the line segments having relevance tothe part of interest in the body pose image, or the contour portioncorresponding to the part of interest in the contour image, to theimageable space of the imaging components. For example, the coordinatesof every point of the line segments bearing the relevance in the bodypose image, and the coordinates of every points of the contour bearingthe relevance in the contour image, will be converted into correspondingcoordinates in the imageable space.

Subsequently into step S803, the image processing unit 230, based on thecoordinates of the line segments bearing the relevance in the imageablespace, determines a physical boundary of the part of interest in theanatomy (e.g., in a two-dimensional rectangular coordinate systemparallel to a imaging plane, the physical boundary may be represented bythe maximum and minimum values of a part of interest on the X and Yaxes).

Upon step S803, the method process illustrated in FIG. 8 goes to stepS804. In the step, the image processing unit 230, based on the boundarydetermined by step S803, determines the plurality of specified positionsof the imaging parameters or imaging components. As an example, thetotal times of imaging or exposure may be determined first; next, theposition of the radiation detector and the X-ray source are determinedevery time imaging is excised (e.g., the stop position of at center ofthe radiation detector and the X-ray source). In the example, providedthe radiation detector and the X-ray source move along the X axis, thetotal times of imaging or exposure may be determined according to theequation below.

$\begin{matrix}{N = {{int}\left( {\frac{L - P}{L_{d} - P} + 1} \right)}} & (2)\end{matrix}$

Here, N is the total times of imaging or exposure; int, as anoperational character, denotes the acquisition of integer part; Ldenotes the length of a part of interest; La indicates the effectiveexposure length of the radiation detector every time exposure isexercised; and, P refers to the minimum exposure overlapping necessaryfor image stitching.

Correspondingly, the position of the radiation detector and the X-raysource every time imaging is excised may be determined according to theequation below.

$\begin{matrix}{H_{N} = \left\{ \begin{matrix}{{{H_{ini} + \frac{L_{d}}{2} + {n \times \left( {L_{d} - P} \right){if}n}} = 1},{{2\ldots\ldots N} - 1}} \\{{{\left. {H_{N - 1} + {\left( {L - \left( {N - 2} \right)} \right) \times L_{d}} + {\left( {N - 3} \right) \times P}} \right)/2}{if}n} = N}\end{matrix} \right.} & (3)\end{matrix}$

Here, H_(n) denotes the position where the radiation detector and theX-ray source are at the n^(th) time of imaging or exposure; and H_(ini)denotes the limit position of the radiation detector and the X-raysource on the X axis (the minimum allowed value of the X axis).

FIG. 9 is a schematic block diagram illustrating the image processingsystem according to another embodiment of this invention. The imageprocessing unit shown in FIG. 2 may be enabled by the image processingsystem of the embodiment.

An image processing system 90, as illustrated by FIG. 9, includes amemory 910 (non-volatile memory such as flash memory, ROM, hard diskdriver, magnetic disk, compact disk), a processor 920 and a computerprogram 930 stored in the memory 910 and executable in the processor920.

In the image processing system illustrated in FIG. 9, the computerprogram 930 is executed to implement the steps included in thelong-length imaging method based on digital radiography as described byFIGS. 3-8.

According to another aspect of the invention, a computer-readable memorymedium with a computer program stored therein is provided. And, thesteps included in the long-length imaging method based on digitalradiography as described by FIGS. 3-8 may be implemented when thecomputer program is executed.

The embodiments and examples are offered in the text to elaborate theimplementation mode according to the technology and its specificapplications in the best way such that one skilled in the art couldimplement and use the present invention. However, as known to all thoseskilled in the art, the above description and examples are offeredsolely for explanation and example citation, and the given descriptionis not intended to cover all the respects of this invention or limit itto the forms exactly disclosed.

1. A long-length imaging method based on digital radiography, the method comprising the steps of: determining a part of interest of an anatomy of an object; determining imaging parameters of digital radiography based on the part of interest, the imaging parameters at least including a plurality of specified positions of imaging components, wherein the plurality of specified positions are configured to make X-ray images captured at the plurality of specified positions by using the imaging components include the part of interest of the anatomy of the object; and generating a long-length image in relation to the part of interest of the anatomy of the object based on the X-ray images at the plurality of specified positions.
 2. The long-length imaging method according to claim 1, further comprising: generating, from an image presenting external features of the object, a body pose image suitable to depict the anatomy of the object, the body pose image including key nodes of the anatomy and line segments indicating relevance between the key nodes; and, determining the line segments having relevance to the part of interest in the body pose image.
 3. The long-length imaging method according to claim 2, further comprising employing an identification algorithm of a human body pose to locate the key nodes of the anatomy.
 4. The long-length imaging method according to claim 2, further comprising including one or more of a neck, shoulder, wrist, elbow, rib, hip, crotch, knee and ankle as a key node.
 5. The long-length imaging method according to claim 1, further comprising: determining, by using an image segmentation algorithm, a contour of the object in the image presenting the external features of the object to generate a contour image depicting the contour of the object; and determining, in the contour image, a contour portion having relevance to the part of interest according to a proportional relation between every parts of the anatomy of the object in a specific body pose.
 6. The long-length imaging method according to claim 1, wherein the part of interest includes one of the following parts: spine, leg bone and arm bone.
 7. The long-length imaging method according to claim 2, wherein the imaging components comprise a X-ray source and a detector.
 8. The long-length imaging method according to claim 7, further comprising: mapping the line segments having relevance to the part of interest in the body pose image to an imageable space of the imaging components; determining boundaries of the line segments in the imageable space; and determining the plurality of specified positions of the imaging components based on the boundaries.
 9. The long-length imaging method according to claim 1, further comprising stitching together the X-ray images captured at the plurality of specified positions by using an image stitching algorithm to generate the long-length image in relation to the part of interest of the anatomy of the object.
 10. A digital radiography device, comprising: an imaging unit, comprising a X-ray source and a radiation detector as imaging components; a control unit, configured to control an imaging process of the imaging unit based on imaging parameters; and an image processing unit configured to: determine a part of interest of an anatomy of an object; determine, based on the part of interest, the imaging parameters required by the control unit to control the imaging process, the imaging parameters at least including a plurality of specified positions of the imaging components, wherein the plurality of specified positions are configured to make X-ray images captured by the imaging components include the part of interest of the anatomy of the object at the plurality of specified positions; and generate a long length image in relation to the part of interest of the anatomy of the object based on the X-ray images captured at the plurality of specified positions.
 11. The digital radiography device according to claim 10, wherein the image processing unit is further configured to execute the following steps: generating, by an image presenting external features of the object, a body pose image suitable to depict the anatomy of the object, the body pose image including key nodes of the anatomy and line segments indicating relevance between the key nodes; and determining the line segments having relevance to the part of interest in the body pose image.
 12. The digital radiography device according to claim 11, wherein an identification algorithm of a human body pose is employed to locate the key nodes of the anatomy.
 13. The digital radiography device according to claim 11, wherein the image processing unit is further configured to execute the following steps: determining, by an image segmentation algorithm, a contour of the object in the image presenting the external features of the object to generate a contour image depicting the contour of the object; and determining, in the contour image, a contour portion having relevance to the part of interest according to a proportional relation between every parts of the anatomy of the object in a specific body pose.
 14. The digital radiography device according to claim 11, wherein the key nodes include one or more of the following parts: neck, shoulder, wrist, elbow, rib, hip, crotch, knee and ankle.
 15. The digital radiography device according to claim 10, wherein the part of interest includes one of the following parts: spine, leg bone and arm bone.
 16. The digital radiography device according to claim 10, wherein the image processing unit is further configured to execute the following steps: mapping the line segments having relevance to the part of interest in the body pose image to an imageable space of the imaging components; determining boundaries of the line segments in the imageable space; and determining the plurality of specified positions of the imaging components based on the boundaries.
 17. The digital radiography device according to claim 10, wherein the image processing unit is further configured to execute the following steps: stitching together the X-ray images captured at the plurality of specified positions by an image stitching algorithm to generate the long-length image in relation to the part of interest of the anatomy of the object.
 18. The digital radiography device according to claim 11, further comprising an image capture device configured to capture the image presenting the external features of the object.
 19. An image processing system, comprising: a memory; a processor; and, a computer program stored in the memory and executable by the processor, wherein execution of the computer program causes the steps of claim 1 to be executed. 